nsprpub/pr/include/prmon.h

Wed, 31 Dec 2014 06:55:50 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Wed, 31 Dec 2014 06:55:50 +0100
changeset 2
7e26c7da4463
permissions
-rw-r--r--

Added tag UPSTREAM_283F7C6 for changeset ca08bd8f51b2

michael@0 1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0 2 /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0 3 * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0 5
michael@0 6 #ifndef prmon_h___
michael@0 7 #define prmon_h___
michael@0 8
michael@0 9 #include "prtypes.h"
michael@0 10 #include "prinrval.h"
michael@0 11
michael@0 12 PR_BEGIN_EXTERN_C
michael@0 13
michael@0 14 typedef struct PRMonitor PRMonitor;
michael@0 15
michael@0 16 /*
michael@0 17 ** Create a new monitor. Monitors are re-entrant locks with a single built-in
michael@0 18 ** condition variable.
michael@0 19 **
michael@0 20 ** This may fail if memory is tight or if some operating system resource
michael@0 21 ** is low.
michael@0 22 */
michael@0 23 NSPR_API(PRMonitor*) PR_NewMonitor(void);
michael@0 24
michael@0 25 /*
michael@0 26 ** Destroy a monitor. The caller is responsible for guaranteeing that the
michael@0 27 ** monitor is no longer in use. There must be no thread waiting on the monitor's
michael@0 28 ** condition variable and that the lock is not held.
michael@0 29 **
michael@0 30 */
michael@0 31 NSPR_API(void) PR_DestroyMonitor(PRMonitor *mon);
michael@0 32
michael@0 33 /*
michael@0 34 ** Enter the lock associated with the monitor. If the calling thread currently
michael@0 35 ** is in the monitor, the call to enter will silently succeed. In either case,
michael@0 36 ** it will increment the entry count by one.
michael@0 37 */
michael@0 38 NSPR_API(void) PR_EnterMonitor(PRMonitor *mon);
michael@0 39
michael@0 40 /*
michael@0 41 ** Decrement the entry count associated with the monitor. If the decremented
michael@0 42 ** entry count is zero, the monitor is exited. Returns PR_FAILURE if the
michael@0 43 ** calling thread has not entered the monitor.
michael@0 44 */
michael@0 45 NSPR_API(PRStatus) PR_ExitMonitor(PRMonitor *mon);
michael@0 46
michael@0 47 /*
michael@0 48 ** Wait for a notify on the monitor's condition variable. Sleep for "ticks"
michael@0 49 ** amount of time (if "ticks" is PR_INTERVAL_NO_TIMEOUT then the sleep is
michael@0 50 ** indefinite).
michael@0 51 **
michael@0 52 ** While the thread is waiting it exits the monitor (as if it called
michael@0 53 ** PR_ExitMonitor as many times as it had called PR_EnterMonitor). When
michael@0 54 ** the wait has finished the thread regains control of the monitors lock
michael@0 55 ** with the same entry count as before the wait began.
michael@0 56 **
michael@0 57 ** The thread waiting on the monitor will be resumed when the monitor is
michael@0 58 ** notified (assuming the thread is the next in line to receive the
michael@0 59 ** notify) or when the "ticks" timeout elapses.
michael@0 60 **
michael@0 61 ** Returns PR_FAILURE if the caller has not entered the monitor.
michael@0 62 */
michael@0 63 NSPR_API(PRStatus) PR_Wait(PRMonitor *mon, PRIntervalTime ticks);
michael@0 64
michael@0 65 /*
michael@0 66 ** Notify a thread waiting on the monitor's condition variable. If a thread
michael@0 67 ** is waiting on the condition variable (using PR_Wait) then it is awakened
michael@0 68 ** and attempts to reenter the monitor.
michael@0 69 */
michael@0 70 NSPR_API(PRStatus) PR_Notify(PRMonitor *mon);
michael@0 71
michael@0 72 /*
michael@0 73 ** Notify all of the threads waiting on the monitor's condition variable.
michael@0 74 ** All of threads waiting on the condition are scheduled to reenter the
michael@0 75 ** monitor.
michael@0 76 */
michael@0 77 NSPR_API(PRStatus) PR_NotifyAll(PRMonitor *mon);
michael@0 78
michael@0 79 /*
michael@0 80 ** PR_ASSERT_CURRENT_THREAD_IN_MONITOR
michael@0 81 ** If the current thread is in |mon|, this assertion is guaranteed to
michael@0 82 ** succeed. Otherwise, the behavior of this function is undefined.
michael@0 83 */
michael@0 84 #if defined(DEBUG) || defined(FORCE_PR_ASSERT)
michael@0 85 #define PR_ASSERT_CURRENT_THREAD_IN_MONITOR(/* PRMonitor* */ mon) \
michael@0 86 PR_AssertCurrentThreadInMonitor(mon)
michael@0 87 #else
michael@0 88 #define PR_ASSERT_CURRENT_THREAD_IN_MONITOR(/* PRMonitor* */ mon)
michael@0 89 #endif
michael@0 90
michael@0 91 /* Don't call this function directly. */
michael@0 92 NSPR_API(void) PR_AssertCurrentThreadInMonitor(PRMonitor *mon);
michael@0 93
michael@0 94 PR_END_EXTERN_C
michael@0 95
michael@0 96 #endif /* prmon_h___ */

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